If you’ve ever reached for a bottle of "Milk of Magnesia" at the pharmacy, you’ve already met magnesium hydroxide. It’s a simple mineral that works as both an antacid to calm stomach acid and a laxative to ease constipation. The chemistry is easy: it reacts with water in your gut to form magnesium chloride and calcium carbonate, which neutralizes excess acid and draws water into the bowels.
Most people use magnesium hydroxide for two reasons. First, as an antacid, a teaspoon of the liquid or chewable tablets can quickly relieve heartburn after a heavy meal. Second, when taken in higher doses, it softens stool and helps you have a regular bowel movement without harsh chemicals.
Because it works locally in your digestive tract, it has fewer systemic effects than some prescription drugs. That makes it popular for occasional use, but it’s not meant for daily long‑term therapy unless a doctor says so.
Start with the lowest dose that gives you relief. For heartburn, a half teaspoon of liquid or one chewable tablet is usually enough. If you need it as a laxative, follow the label—typically 1‑2 teaspoons for adults—but never exceed the recommended amount.
Take magnesium hydroxide with a full glass of water. The extra fluid helps it work faster and reduces the chance of stomach cramps. If you’re on other meds, space them out by at least two hours; magnesium can interfere with absorption of antibiotics or thyroid pills.
Watch for side effects: mild diarrhea is common when you take too much, and some people feel a bit of nausea. If symptoms persist for more than a few days, stop using it and talk to a pharmacist or doctor.
Shopping online saves time, but you need to avoid fake products. Stick with reputable pharmacies that require a prescription for higher doses or have clear contact info and customer reviews. Look for certifications like the Canadian Pharmacy Association logo; they signal compliance with safety standards.
Check the expiration date before buying. Magnesium hydroxide can lose potency over time, especially if stored in hot places. If a deal looks too good to be true, it probably is—cheap knock‑offs may contain fillers that cause unwanted reactions.
Can I use magnesium hydroxide while pregnant? It’s generally safe for occasional heartburn relief, but talk to your OB‑GYN before using it as a laxative.
Is it okay for kids? Children can use lower doses of the liquid form, but always follow pediatric guidelines or ask a pharmacist.
Will it interact with my blood pressure meds? Magnesium can affect how some drugs are absorbed. Keep a two‑hour gap between magnesium hydroxide and any prescription you take.
Bottom line: magnesium hydroxide is a handy, over‑the‑counter tool for occasional heartburn or constipation. Use the smallest effective dose, stay hydrated, and buy from trustworthy online pharmacies. When in doubt, a quick call to your local pharmacist can clear up most questions and keep you on the safe side.
